An interlock mechanism as contemplated by the present invention is used in the drive line of a vehicle for releasably locking a driven member to a drive member. A specific example is a hub lock (interlock mechanism) for locking and unlocking a wheel hub (a driven member) to a wheel axle (a drive member).
Actuating mechanisms are provided for actuating a hub lock mechanism that is referred to as a pulse actuated interlock mechanism. The mechanism includes a piston and latch member that responds to a force, e.g., air pressure (negative or positive). The force moves the piston which moves a clutch ring to an interlocking relation with both the driven and drive members. The piston is latched to the latch member. The force is withdrawn whereas the piston is retained in the latched position. (The force which moves the piston to the latched position and is then withdrawn is here referred to as a first pulsating force.) A second pulsating force moves the piston relative to the latch member to release the latched engagement and the piston is returned to a withdrawn position. The clutch ring is moved to an engaged position and a disengaged position in response to unlatching and latching of the piston and latch member.
The latching mechanism relies on relative movement of the piston and latch members to accomplish latching and unlatching of the piston. The latch member is a cam-like member rotatively fixed and provided on the inner wall of the housing for the interlock mechanism.
Other hub locks are known in which a positive or negative pressure is utilized to constantly maintain the interlock mechanism in an engaged or disengaged position. With many of these known interlock mechanisms, both of the pulse activated and constantly applied pressure types, it is a challenge to provide a sealed connection path between the vacuum fitting and the rotating interlock mechanism. Previously, the vacuum fitting was provided in the steering knuckle which required large elaborate seals to be used between the steering knuckle and axle shaft.
The present invention provides a vacuum path for an interlock mechanism that extends through the wheel bearing and then to the wheel hub. Providing the vacuum path through the wheel bearing allows the wheel hub disconnect technology to be easily applied with minimal change to the existing wheel end or knuckle designs.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.